Gas-engine.



. No. 745,266. v PATENTBD Nov.2,4,19os.

c. W. TRBMAIN.`

GAS ENGINE.

APPLIUATION FILED AUG. so, 1901. No MODEL. JC 1 NE Nonsls PETERS co. PHOTGLWHD., WASHINGTON. D. c.

UNITED STATES Patented November 24, 1903.

PATENT OFFICE.

CHARLES WV. TREMAIN, OF CHICAGO, ILLINOIS, ASSIGNOR OF ONE-HALF'. TO FRANK E. TREMAIN, OF CHICAGO, ILLINOIS.

GAS-ENGINE.

SPECIFICATION forming part of Letters Patent No..745,266, dated November 24, 1903.

Application metingen 30.1901.' serai No. 73.889. (No motti.)

To a/ZZ wwm t may concern/.-

Beit known that I, CHARLES W. TREMAIN, a citizen of the United States, residing at 886 Warren avenue, Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Gas- Engines, of which the following is a speciiction. y

My invention relates to improvements in gas-engines of the two-cycle type.

The principal object of my invention is to provide such an engine so constructed that the expansion of gases therein may be utilized as the motive force until such gases have expanded to substantiallyatmospheric pressure. This I accomplish, generally speaking, by utilizing the initial expansion of the gases to drive the piston in one direction and the further expansion of the gases to assist the return stroke of the piston and so, also, to assist in the compression of the explosive mixture in the compression-cylinder.

So it is among the objects of my invention to produce a higher and purer compression of the explosive mixture and to obtain greater eiciencyfrom the quick and complete expansion thereof, together with an accelerated movement vof the piston at every stroke.

A further object of my invention is to produce an engine of'this type which shall involve reduced friction, less vibration, have a mild exhaust without the aid of a mufie, and which may be operated in either direction without manipulating the Valve-gear.

All engines of this type are operated primarily by admitting anexplosive mixture to a cylinder containing a piston and then ig niting such mixture, the resultant expansion of the explosion of the mixture forcing the piston lengthwise of the cylinder. As commonly constructed when the 'piston reaches the end of its stroke the still heated and still expanding gases are allowed to escape from the cylinder through nthe exhaust. Careful tests have demonstrated that with an engine so constructed the gases' escape yfrom the exhaust at a high pressure andat a high tem-- perature. Consequently this construction not only results in a great Waste'of power, but, owing to the high pressure at 'which the gases chamber and which is subjected to pressure of the expanding gases within the explosionchamber has but a part of the total area of the piston-head. y

K Adjacent to the extreme outer end of the 'explosion-chamber is an expansion-chamber, free communication between which and the explosion-chamber is opened as the piston reaches the end of its forward stroke. The surface of the piston-head, which is exposed to the pressure of gases within this expansion-chamber, is so proportioned with relation `to the area of the opposite face of the piston-head, which is exposed to the expansion of gases within the explosion-chamber, that when the expanding gases lescape from the explosion-chamber intoI the expansionp chamber their pressure against the outer face of the piston-head will tendto force the piston back into the explosion-chamber, and thus assist the piston on its back stroke. As the back stroke of the piston carries the piston-head into the explosion-cylinder the cubic area of the expansion-chamber increases until the gases 'have expanded to or below atmospheric pressure, whereupon upon the next forward stroke of the piston the cooled and expanded gases are forced from the exhaust without heat, pressure, or noise. 'It will thus be seen that I not only utilize the Vsecondary expansion of the gases toaccelerate the return stroke of the piston, but where the engine is constructed as shown in the drawings, so that the piston is provided with a secondary piston-head, which moves within a compression -cylinder, so that the return stroke of the piston is utilized to compress the explosive mixture, I succeed by means of this secondary expansion of the gases in producing a greater compression ofthe explosive mixture than could otherwise be readily obtained, which in turn results in a greater eficiency when the mixture so compressed is exploded in the explosion-cylinder.

These and such other objects as may hereinafter appear are attained by the devices illustrated in the accompanying drawings, in which my invention is shown as embodied in an engine of the oscillating class although my improvement is not confined to use in connection with this class of motor.

In the accompanying drawings, Figure lis a horizontal section of au oscillating engine embodying my improvements. Fig. 2 is a side View, partly in section and partly in elevation. Fig. 3 is a view, partly in section, on the line 3 3 of Fig. 2 looking in the direction indicated by the arrows; and Fig. 4 is a similar view on the line 4 4E of Figs. l and 2 looking in the direction indicated by the arrows.

Like characters of reference indicate the same parts in the several figures of the drawings.

The form of engine shown is provided with an explosion-cylinder A, arranged tandem with a compression-cylinder B. C is a piston provided with piston-heads a b, fitting within the cylinders A B, respectively. That portion of the stem of the piston C which is arranged to move within the explosion-cylinder A is so proportioned with relation to the piston-head and the explosion-cylinder that the open space within the explosion-cylinder is reduced to constitute the annular explosionchamber A', while the portion of the inner face of the piston-head u which is exposed to the pressure of gases within the explosionchamber A' is reduced to the annular surface a', which constitutes a movable end wall to the explosion-chamber A'.

Opening from the forward end of the explosion-chamber A is an expansion-chamber D, arranged to be in free communication with the explosion-chamber A as the piston-head a reaches the forward end of its stroke. The dimensions of the expansion-chamber D and the area of the outer face of the piston-head a, which is exposed within the expansionchamber D are so proportioned with relation to the area of the inner face of the piston-head ct which is exposed within the explosion-chamber A that when the expanding gases escape from the explosion-chamber A' into the expansion-chamber D the continued expansion thereof will force the piston-head a. backward into the explosion-chamber A.

The piston head a is provided with the chamber 1, from which a port 2 communicates with the expansion-chamber D, while ports.

3 3 communicate with the explosion-chamber A. Mounted within the chamber l is a valve E, so constructed and arranged that when in its extreme open position the area of the exposed outer face of the valve will be much greater than the area of that portion of the inner face of the valve which is exposed to pressure within the chamber l. In practice I have found it effective to have the area of the exposed outer face of the valve three times that of the exposed inner face of the valve; but I do not confine myself to any such arbitrary proportions.

The expansion-chamberD is preferably provided with a number of diagonally-arranged supports d for guiding the piston-head a during its travel Within the expansion-chamber D; but other suitable and well-known means may be substituted for this purpose without departing from `the spirit of my invention.

The compression-chamber B is provided with an explosive mixture through a pipe F, which passing through a slotfin the frame of the machine communicates with a passage G, which opening through the trunnion H extends through t-he casing of the engine to a suction-valve I, whence a passage J communicates with the interior of the compressioncylinder. Upon the forward stroke of the piston the explosive mixture is drawn into the cylinder B, whereupon on the back stroke of the piston the suction-valveI is automatically closed and the explosive mixture is forced out of the compression-cylinder through a passage-way K, a check-valve L, a passage M, and thence into an annular passage N, which surrounds a piston-valve O and communicates with the piston side of said valve through ports P.' From the piston-valve O a port or passage Q communicates with the explosionchamber A.

By means of the eccentric R, mounted upon the axle of the iiy-wheel, the strap S, and levers T and U the piston-head O is opened during the return stroke of the main piston and is closed as soon as the charge of explosive mixture has been forced into the explosion-chamber A'. Thereupon by a suitable device, such as the sparker U, the mixture within the explosion-chamber is ignited and expanding drives the piston-head A forward until the forward movement of the pistonhead opens free communication between the explosion-chamber A and the expansioncharnber D, whereupon the still-expanding gases fill the expansion-chamber D and acting against the greater area of the exposed outer face of the piston-head a force the piston back within the expansion-chamber A', at the same time forcing the valve E open. As the piston moves on its hack stroke the gases remaining in the expansion-chamber A' escape through the ports 3 3 and the port l into the expansion-chamber D. At the same time as the back stroke of the piston increases the space within the expansion-chamber D the gases within said chamber continue to expand, with a resultant decrease of pressure, and when the piston-valve O opens and admits the explosive mixture under pressure to the explosion-chamber A the superior pressure IOO IIO

thereof 'exerted against the inner face of the valve E closes the valve E, and the engine is ready for the explosion of the charge and theY next forward stroke. 'Meanwhile by means of the rod V, connected with the gear of the engine and provided with an arm o, abutting against a collar 'tu on the stem of the exhaustvalve W, the exhaust-valve is opened, and the next forward stroke of' the piston forces the now cool and expanded gases out of the exhaust without noise, pressure, or heat. As soon, however, as the next charge of expanding gases is admitted to the expansion-chamber D the exhaust-valve W is automatically closed by the pressure of the gases within the chamber D, and the movement of the parts continues as beforewith constantly-accelerated speed.

While I have shown and described certain means for admitting the explosive mixture to'the compression-cylinder and for thence transmitting it to the explosion-cylinder, my invention is not confined to the employment of the precise means shown, as many ways are known in this art for charging the compression and expansion cylinders of the engine, and, indeed, the means shown by me may be differently arranged-as,for instance., by arranging the supply-pipe F axially of the trunnion H in a manner similar to that in which the'water-pipe X for supplying the water-jacket is arranged in the trunnion H. So, also, the sparking device U may be suitably attached to the expansion cylinder at any desirable point.,

It will be observed that an engine constructed as above shown will readily operate the liy-wheel or a power-wheel in either direction, it only being necessary in starting the engine to give the initial turn to the fly-wheel in the direction desired until the iirst charge has been compressed within the compressioncylinder and exploded within the explosionchamber, whereupon the engine will continue to operate without further manipulation until stopped in any usual manner.

I claiml. In an explosive-engine, the combination with an explosion-chamber and an expansionchamber of larger diameter communicating therewith, of a differential piston tted to said explosion-chamber, having its smaller area exposed within said explosion-chamberA chamber to the expansion-chamber, and a pressure-actuated valve located in said piston and arranged to be opened by pressure within said expansion-chamber and to be closed by superior pressure within the explosion-chamber, substantially as described.

4. An explosive-engine, comprising an explosion-chamber, a piston provided with a piston-head arranged to travel within said explosion-chamber, an expansion chamber., means for controlling communication between said chambers, whereby said communication is opened as the piston-head nears the outer extreme ot its travel and is closed upon the return stroke of the piston, said piston being provided with a passage-way for the escape of gases from the explosion-chamber upon the return stroke of the piston, and pressure-actuated means for closing said passage when a fresh charge of explosive mixture is admitted to the explosion-chamber,substantially as described.

5. In an explosive-engine, the combination with a compression-cylinder, of an explosion-- cylinder, an expansion-chamber communicating with said explosion-cylinder and 5f larger diameter than said explosion-cylinder, a pistonhead arranged to it and travel within said compression-cylinder, and a piston-head so arranged to't and travel within said explosion-cylinder that, as it approaches the end of its outward stroke, it will open communication between said explosion-cylinder and said expansion-chamber, substantially a's described..

6. An explosive-engine, comprising an explosion-chamber, an expansion-chamber of larger diameter than said explosion-chamber and communicating with one end of said explosion-chamber, and a piston arranged to tit and travel within said explosion-chamber and to open communication between said explosion-chamber and said expansion-chamber, when near the outer end of its stroke, substantially as described.

7. An explosive-engine, comprising an explosion-chamber, an expansion-chamber of greater diameter than said explosion-chamber and communicating with one end of said explosion-chamber, a piston arranged to t and travel within said explosion-chamber, so as to open communication with said expansion-chamber, when said/piston approaches the outer end of its stroke, the head of said piston being provided with avalve-ohamber, In testimony whereof I aix my signature a port; leading from said Valve-chamber to in tbe presence of two witnesses. said expansiomehamber, a valve arranged to CHARLES W TREMAIN alternately close and unolose said porb, and

5 a passage providing communication between Witnesses:

said Valve-chamber and said explosion-cham- JAS. K. TREMAIN, ber, substantially as described. l I. HAMILTON. 

